All objects with a temperature above absolute zero emit heat energy in the form of radiation. An infrared sensor is a device used to sense infrared radiation. Using a pixelated infrared sensor such as in for instance an infrared camera, an image can be obtained using infrared radiation instead of visible light. Infrared radiation ranges from approximately 0.75 micrometers to 1000 micrometers and the spectral selectivity of a pixelated infrared sensor may be limited by means of a pass-band filter determining a wavelength band of operation of the pixelated infrared sensor.
Infrared cameras may be used in a wide range of applications such as security and defense as well as industrial applications. In particular, infrared cameras may be used for gas detection applications or various types of surveying applications wherein a substance (such as a gas) to be detected emits, reflects and/or absorbs infrared radiation within a specific wavelength band. However, the information provided by current infrared imaging sensors is still limited and a number of processing steps may be required for determining presence of such substance in an image captured by the imaging sensor. In general, imaging sensors providing a more reliable detection are desired. For at least those reasons, there is still a need of improved infrared imaging sensors.